[Dxbase] LOTW problem

[Stan]

I am not sure if this is a DXBase problem, an LOTW problem, a cockpit
problem, or what. When I save a portion of my log using the selection wizard
into an adif file, and then "sign" the file using tqsl, I get the following
error message:

Signing using CALL=W4AG, DXCC=291
Error: Certificate QSO date out of range on line 12
CALL: 2E0COO
QSO_DATE: 20100318
TIME_ON: 023626
FREQ: 3.77200
BAND: 80M
MODE: LSB

Error: Certificate QSO date out of range on line 18
CALL: 3B8CF
QSO_DATE: 20100213
TIME_ON: 140011
FREQ: 24.89269
BAND: 12M
MODE: CW

Error: Certificate QSO date out of range on line 24
CALL: 3B8CF
QSO_DATE: 20100817
TIME_ON: 025303
FREQ: 7.00385
BAND: 40M
MODE: CW

Every sixth line is cited as a "date out of range" error, even though the
dates are definitely within the range I used in the wizard. I have only
shown the first three here, but every sixth line is cited as an error
throughout the 1000+ records I saved.

Does anyone have any idea what might be causing this?

Thanks,
Stan, W4AG